Beginning in the fifties and sixties, the flood tide of cheap corn made it profitable to fatten cattle on feedlots instead of on grass, and to raise chickens in giant factories rather than in farmyards. Iowa livestock farmers couldn’t compete with the factory- farmed animals their own cheap corn had helped spawn, so the chickens and cattle disappeared from the farm. and with them the pastures and hay fields and fences. In their place the farmers planted more of the one crop they could grow more of than anything else: corn. And whenever the price of corn slipped they planted a little more of it, to cover expenses and stay even. By the 1980s the diversified family farm was history in Iowa, and corn was king.

Michael Pollan

Source: The Omnivore's Dilemma: A Natural History of Four Meals (Large Print Press), Pages: 38